Free Contour Map Generator

Last updated 2026-10-21 · MapElevation

Generate contour lines for a location

A contour map generator provides a continuous visual structure for terrain that is harder to see from isolated point numbers. Choose a location on the map or enter coordinates, zoom in, and select a contour interval. The map draws lines derived from the loaded elevation source. The initial view starts near varied terrain so that the layer has a useful context, rather than requiring you to locate a mountain range from a world view.

Use the elevation finder when the exact height at a known coordinate is your main question. The elevation map is better for broad browsing and shaded relief. If you are looking for a house, begin with the address elevation finder, review the matched position, and remember that a street-address match does not turn the contour layer into a building survey.

How to use this page

1. Choose a location or enter a coordinate, then zoom into the terrain.
2. Select a contour interval in metres.
3. Compare line spacing and labels with the terrain context and point result.
4. Retain the source limitations and use a suitable survey for design work.

How contours are derived from elevation data

The source tiles encode a grid of surface elevations. The contour process looks for crossings of the selected height levels between samples and builds lines representing those equal-height paths. The implementation uses the open-source maplibre-contour project with the configured terrain source. The calculation happens for map tiles rather than through a new field measurement.

The layer and the point-elevation result describe related views of the same modeled surface. They are not independent confirmations of each other. If a tree canopy or building affects the DSM, it can affect the line shape as well as the point reading. The elevation data accuracy guide explains the active dataset and why original spacing, display zoom, and vertical uncertainty must be considered separately.

Choose a contour interval

The interval is the vertical difference between successive contour levels. A broader interval usually produces fewer lines and a clearer view of large terrain features. A narrower interval can help inspect smaller modeled changes, but it also increases visual density. Choose it for the task and terrain rather than treating the finest available selection as inherently better information.

The tool labels the interval in metres and displays some line labels for orientation. Those labels use the dataset’s height reference. If your input came from a GPS receiver, read what is my altitude above sea level before comparing the line labels with the receiver’s altitude display. Converting units does not resolve a mismatch between an ellipsoid height and a geoid-based terrain source.

Read contour spacing and terrain shape

Close lines suggest a steeper modeled change, while wider spacing suggests gentler terrain. Nested shapes can help you recognise hills and depressions, but do not infer which is which from a single unlabeled loop. Read height labels and nearby terrain context together. Hillshade can support interpretation, although light and shadow are not height values themselves.

A map line also has a rendering width and an interpolation method. Its screen position should not be read as a surveyed boundary with exact ground coordinates. Zooming in makes the drawing larger without creating new original samples. For what is my elevation at a particular spot, inspect the point result and source label rather than trying to estimate a precise value from a thick line on screen.

What contours cannot tell you

These lines do not identify a parcel boundary, the height of a particular floor, the capacity of a drain, or the validity of a construction design. A narrow wall, ditch, embankment, or small structure can be poorly represented at the current scale. A continuous-looking contour should not be mistaken for a guarantee about how water will flow around such a feature.

For coastal questions, the sea level rise map explains the separate connectivity assumptions behind its demonstration. For US mapped hazards, use flood zone by address; contours alone do not reproduce FEMA’s study. A browser check at latitude 39.7392, longitude −104.9903 returned 5,238 ft from the same source policy as the recorded 1,596.5 m tile sample on 2026-10-21. The contour display and a change from the 100 m to the 50 m interval were also exercised. An independent contour-position comparison remains pending; this observation does not validate the lines as a survey. No export or survey-grade accuracy is implied by this first interactive version.